CHUNG, HYONDO, M.S., Examination of Low Socio ...CHUNG, HYONDO, M.S., Examination of Low...
Transcript of CHUNG, HYONDO, M.S., Examination of Low Socio ...CHUNG, HYONDO, M.S., Examination of Low...
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CHUNG, HYONDO, M.S., Examination of Low Socio-economic Status Pregnant
Women’s First Trimester Exercise Intention and Behavior. (2012)
Directed by Dr. Diane L. Gill. 59pp.
Exercise is a safe and efficacious way to gain many physical and mental health
benefits (Fell, Joseph, Armson, & Dodds, 2008). However, the majority of women stay
sedentary during pregnancy (Evenson & Well, 2010). In order to promote exercise
among pregnant women, Hausenblas, Symons Downs, and their colleagues conducted
a series of studies to explore psychosocial determinants that impact middle-to-upper
class women’s physical activity during pregnancy (Hausenblas & Symons Downs,
2004; Hausenblas, Symons Downs, Giacobbi, & Cook, 2008; Symons Downs &
Hausenblas, 2003, 2007). However, research indicates socio-economic status (SES) as
a significant predictor of different physical activity levels during pregnancy
(Domingues & Barros, 2007; Cheng et al., 2011). Thus low SES pregnant women may
have different psychosocial determinants of exercise. This study is designed to
replicate the previous study of Hausenblas and Symons Downs (2004) to examine low
SES pregnant women’s exercise intention and behavior.
Participants were 50 low-socioeconomic status women who were in their first
trimester of pregnancy. They were recruited from a local social program which
provides financial assistance for obstetric check-ups during pregnancy. All participants
completed a questionnaire packet which was designed to measure psychosocial
determinants of exercise (TPB) and physical activity. Demographic information was
also collected.
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Results from multiple regression analysis indicated that the TPB constructs;
attitude, subjective norm, and perceived behavioral control, did not predict exercise
intention. Discriminant analysis results revealed that exercise intention and perceived
behavioral control significantly discriminated the exercise and non-exercise group. A
follow-up (step-wise discriminant analysis) indicated that only perceived behavioral
control, but not intention, significantly discriminated the two groups. The results only
partially supported the previous study of Hausenblas and Symons Downs (2004), and
suggest that different variables may have moderated the relationship between the TPB
measure and exercise behavior.
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EXAMINATION OF LOW SOCIO-ECONOMIC STATUS PREGNANT
WOMEN’S FIRST TRIMESTER EXERCISE
INTENTION AND BEHAVIOR
by
Hyondo Chung
A Thesis Submitted to
The Faculty of The Graduate School at
The University of North Carolina at Greensboro
in Partial Fulfillment
of the Requirements for the Degree
Master of Science
Greensboro
2012
Approved by
Committee Chair
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© 2012 Hyondo Chung
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To my parents.
Without their guidance, sacrifice, and infinite love,
I would not have achieved any significant milestone in my life.
To Jinsun.
For her inspirational spirit and unwavering love.
And, to Swan.
For the bundle of joy she brought into my life.
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APPROVAL PAGE
This thesis has been approved by the following committee of the Faculty of
The Graduate School at The University of North Carolina at Greensboro.
Committee Chair _________________________________
Committee Members _________________________________
_________________________________
____________________________
Date of Acceptance by Committee
____________________________
Date of Final Oral Examination
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ACKNOWLEDGMENTS
First, many thanks to my advisor Dr. Diane L. Gill, whose support, leadership,
and patience has made my initial graduate studies successful. I would also like to thank
my committee members, Dr. Paul G. Davis and Dr. Jennifer L. Etnier, for their
assistance in refining this study. Additionally, I would like to acknowledge Jeffrey D.
Labban and Steven A. Seeberg, for their assistance and support that made my two
years at UNCG productive and enjoyable.
This work was supported by Korea Foundation of the Next Generation Sports
Talent (Korea NEST Foundation).
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TABLE OF CONTENTS
Page
LIST OF TABLES ............................................................................................................. vi
CHAPTER
I. INTRODUCTION ............................................................................................ 1
II. REVIEW OF LITERATURE ........................................................................... 6
III. METHODS .................................................................................................... 22
IV. RESULTS ....................................................................................................... 28
V. DISCUSSION ................................................................................................ 34
REFERENCES ................................................................................................................. 39
APPENDIX A. MEASURES ............................................................................................ 47
APPENDIX B. CONSENT FORMS ................................................................................ 55
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LIST OF TABLES
Page
Table 1. Demographic characteristics of sample .............................................................. 29
Table 2. Correlations, means, and standard deviations of the TPB constructs ................. 31
Table 3. Multiple regression analysis results for prediction of exercise intention ............ 32
Table 4. Discriminant analyses results for predicting exercise behavior .......................... 33
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CHAPTER I
INTRODUCTION
Pregnancy is an event with many physiological and psychological changes for
women (Symons Downs & Hausenblas, 2003). For example, pregnant women experience
weight gain, increased cardiac output and thyroid volume, depression, and increased
anxiety (Koniak-Griffin, 1994). Pregnancy also affects women’s exercise behavior, and
many women choose to discontinue or spend less time in regular exercise during this
period (Bungum, Peaslee, Jackson, & Perez, 2000).
The health benefits of regular exercise are well established. According to the
United States Department of Health and Human Services (USDHHS, 2000), physical
activity participation on a regular basis makes a positive contribution to people’s physical
and mental health. Pregnant women who engage in regular exercise can also obtain
positive health outcomes (Lokey, Tran, Wells, Myers, & Tran, 1991; Symons Downs &
Hausenblas, 2003). Exercise during pregnancy is associated with improved physical
fitness (Clapp, Rokey, Treadway, Carpenter, Artal, & Warrens, 1992; Marquez-Sterling,
Perry, Kaplan, Halberstein, & Signorile, 2000), less excessive weight gain (Polley, Wing,
& Sims, 2002), lower cardiovascular risk (Clapp, 2008), better placental and
fetoplacental development (Jackson, Gott, Lye, Knox-Ritchie, & Clapp, 1995; Clapp,
Kim, Burciu, & Lopez, 2000), decreased depression symptoms and increased self-esteem
(Koniak-Griffin, 1994), and improved body image (Marquez-Sterling et al., 2000).
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Exercise guidelines for pregnant women delineate the safety and effectiveness of
regular physical activity, and encourage women to exercise regularly during pregnancy.
The American Congress of Obstetricians and Gynecologists (ACOG, 2002)
recommends pregnant women follow the exercise guidelines of the American College of
Sport Medicine (ACSM, 2006), that is, 30 minutes or more of moderate to vigorous
exercise a day on most days of the week. The USDHHS (2008) guidelines advise 150
minutes or more of moderate aerobic exercise per week for pregnant women who were
not frequently engaging in physical activity before pregnancy. Women who were already
highly active or had been exercising regularly before pregnancy may continue to do so
with some adjustments made upon the recommendations of a health-care provider.
Despite the health benefits and guidelines for exercise, a large number of women
stay sedentary during pregnancy. Approximately two-thirds of pregnant women stay
sedentary (Zhang & Savitz, 1996) and only a small number meet the ACOG (2002)
exercise guideline (Evenson, Savitz, & Huston, 2004; Evenson & Wen, 2010).
In order to promote exercise among pregnant women, Hausenblas, Symons Downs, and
their colleagues conducted a series of studies to explore the factors that impact women’s
physical activity during pregnancy (Hausenblas & Symons Downs, 2004; Hausenblas,
Symons Downs, Giacobbi, & Cook, 2008; Symons Downs & Hausenblas, 2003, 2007).
All studies used the Theory of Planned Behavior ([TPB], Ajzen, 1991) to examine
pregnant women’s exercise behavior. The TPB is a social cognitive theory proposed by
Ajzen (1991) to guide research on understanding and predicting human behavior. The
TPB has been widely applied in sport and exercise psychology to explain exercise
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behavior (Biddle & Nigg, 2000). The TPB postulates that a person’s intention and
perceived behavioral control of performing a behavior is the key determinants of their
behavior, and intention is determined by three components: attitude, subjective norm, and
perceived behavioral control. Attitude reflects personal evaluation toward a certain
behavior. For example, pregnant women may not exercise because they believe it may
hurt the fetus. Subjective norm is the perceived social pressure to perform or not to
perform a behavior. For example, a woman may exercise because she perceives that her
spouse wishes her to control excessive weight gain during pregnancy. Perceived
behavioral control is a person’s perceived capability of performing the behavior.
Perceived behavioral control may affect behavior directly by itself or indirectly via its
influence on intention. For example, pregnant women’s perceived capability of exercise
will influence their exercise intention and behavior. Generally, research in the exercise
domain indicates that intention and perceived behavioral control significantly predict
exercise behavior, and attitude is the most powerful determinant of intention followed by
perceived behavioral control, and subjective norm (Hagger, Chatzisarantis, & Biddle,
2002; Hausenblas, Carron, Mack, 1997).
Past research using the TPB framework found pregnant women’s exercise
intention and perceived behavioral control predicts exercise behavior, and that the
influence of attitude, subjective norm, and perceived behavioral control on exercise
intention varies across the first, second, and third trimester of pregnancy (Hausenblas &
Symons Downs, 2004; Symons Downs & Hausenblas, 2003, 2007). Particularly, during
the first trimester of pregnancy, perceived behavioral control was the strongest predictor
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of exercise behavior, and attitude and subjective norm predicted exercise intention better
than perceived behavioral control. During the second trimester, only intention predicted
exercise behavior, and attitude was the strongest predictor of exercise intention. Lastly,
during the third trimester, intention predicted exercise behavior and subjective norm
predicted exercise intention. However, the majority of participants represented the
middle-to-upper class population (family income between $40,000 and $100,000); thus,
to date, pregnant women’s exercise behavior and intention in low socio-economic status
(SES) is unknown and requires further research. The purpose of this study is to replicate
the previous study of Hausenblas and Symons Downs (2004) with low SES pregnant
women to examine their exercise behavior and intention during the first trimester within
the framework of the TPB.
Research Questions
Research questions are related to the TPB as applied to exercise behavior of
pregnant women. According to the TPB model, attitude, subjective norm, and perceived
behavioral control predict exercise intention. Also, exercise intention and perceived
behavioral control both predict exercise behavior. So, research questions are: 1) do
pregnant women’s first trimester exercise attitude, subjective norm, and perceived
behavioral control predict their exercise intention; and 2) do pregnant women’s first
trimester exercise intention and perceived behavioral control predict their exercise
behavior. It is hypothesized that, based on past literature; 1) attitude, subjective norm, and
perceived behavioral control predict women’s exercise intention during the first trimester
of pregnancy with attitude and subjective norm as the strongest predictors, and 2)
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exercise intention and perceived behavioral control predict women’s first trimester
exercise behavior with perceived behavioral control as the strongest predictor.
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CHAPTER II
REVIEW OF LITERATURE
In this chapter, research on exercise during pregnancy is reviewed. This literature
review begins with a review of both physiological and psychological benefits of exercise
during pregnancy, followed by current guidelines of exercise for pregnant women, and
literature about exercise prevalence among pregnant women. The review continues with
describing the Theory of Planned Behavior ([TPB], Ajzen, 1991) as a theoretical model
of predicting exercise behavior. Then, recent research using the TPB to examine pregnant
women’s exercise behavior is reviewed, followed by the limitation of the study.
Physiological Benefits of Exercise during Pregnancy
The majority of empirical studies indicate that exercise during pregnancy has a
positive physiological influence on the pregnant mother, the fetus, and ultimately the
newborn child (Clapp et al., 1992). Pregnant women’s aerobic fitness was significantly
improved as a function of participation in regular exercise program (Marquez-Sterling et
al., 2000). A total of 15 sedentary primigravidae, which is defined as a woman who is
pregnant for the first time, were randomly assigned to an exercise group (n=9) and a
control group (n=6). The exercise group trained with a target heart rate 150-160
beats/min, three times a week for fifteen weeks. The exercise program included rowing,
cycling, walk-jogging, rhythmic calisthenics, and brisk walk sessions. Fitness was
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measured pre and post using a graded exercise test on a treadmill, which led to 150
beats/min. The results from the study suggested that vigorous-intensity exercise
significantly improved women’s aerobic fitness during pregnancy without any negative
health effects occurring to the mother or the fetus.
Research suggests that exercise helps to control women’s excessive weight gain
during pregnancy (Polley et al., 2002). A total of 120 normal-weight pregnant women,
who were in less than 20 weeks of gestation, were randomly assigned to either a
behavioral intervention or a control group. The behavioral intervention was designed for
promoting appropriate weight gain during pregnancy and postpartum by healthy eating
and exercise. Researchers followed participants’ weight gain through pregnancy to
postpartum, and found that the intervention significantly reduced the number of
participants with an excessive weight gain.
Research also suggests that exercise during pregnancy is positively related to
pregnant women’s long-term exercise adherence and fitness. In a longitudinal study,
Clapp (2008) followed up a cohort of women’s (n=39) exercise patterns, fitness
indicators (BMI, flexibility, & VO2 Max) cardiovascular risk factors (blood pressure,
cholesterol level) and exercise patterns after 18-20 years after their pregnancy. At
baseline, the majority of participants (> 75%) followed the ACSM exercise
recommendation, and all participants voluntarily choose whether or not to exercise during
pregnancy. As a result, women who exercised during pregnancy were more likely to
engage in regular exercise at a higher intensity, and significantly better in most of fitness
and cardiovascular health parameters.
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Yeo (2009) conducted a randomized controlled trial to see the effect of stretching
and walking exercise during pregnancy on preventing preeclampsia risk factors. With 124
pregnant women who had oxygen consumption level below 50th
percentile in their age
group and sedentary lifestyle of expending less than 840 kcal/week on leisure time
physical activity measured by the Minnesota Leisure Time Physical Activity
Questionnaire (Pereira et al., 1997). All subjects participated in either stretching with no
elements of aerobic and muscular resistance or moderate-intensity walking program.
Preeclampsia risk factors (HR, BP, & weight gain) were measured weekly. Both exercise
programs were found beneficial in alleviating the risk of preeclampsia. However, women
showed better adherence to stretching than the walking exercise program, as pregnancy
advanced.
Exercise also has a positive effect on the growth of an unborn child. Jackson et al.
(1995) examined the effect of aerobic exercise during pregnancy on the placental
development by examining the placentae obtained from 60 women after the delivery.
Pregnant women who exercised at least 30 minutes, three or more times a week at
moderate to high intensity, throughout or in the early stage of the index pregnancy were
defined as the exercise group. The control group did not exercise regularly at moderate to
high intensity, but maintained an active lifestyle such as working, gardening, camping,
etc., throughout the pregnancy. Compared to the group of 20 women in the control group,
the 40 women who engaged in regular exercise either in the early pregnancy (before 20
weeks) or throughout the pregnancy had healthier and well developed placentae.
Similarly, weight-bearing exercise during pregnancy significantly improved the birth
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outcome (Clapp et al., 2000). Women (n=46) who were at 8 weeks of pregnancy and did
not engage in regular exercise were randomly assigned into no exercise control group and
weight-bearing exercise experimental group. The experimental group exercised for 20
minutes 3-5 times a week at a moderate intensity of 55-60% of their maximum aerobic
capacity. The exercise program included treadmill runs, step aerobics, and stair stepper
exercises, and lasted throughout the pregnancy. As compared to the control group, the
weight-bearing exercise intervention group had significantly healthier (i.e., heavier and
longer) offspring and more finely developed fetoplacentae.
Psychological Benefits of Exercise during Pregnancy
The majority of empirical studies also indicate that exercise during pregnancy is
associated with many psychological benefits (Symons Downs & Hausenblas, 2003). In
Koniak-Griffin’s quasi-experimental study (1994), 35 of 58 pregnant adolescents
voluntarily completed the aerobic exercise program (AEP) intervention, and the rest were
a non-exercise control group. A single session of AEP consisted of 10 minutes of warm
up, 30 minutes low intensity (< 140 bpm) walking and marching, 15 minutes of
calisthenics, and 10 minutes of cool down. Participants in the AEP group exercised twice
a week for six weeks. Participants who regularly engaged in the AEP showed a
significant decrease in depressive symptoms as measured by The Center for
Epidemiological Studies Depression Scale (CES-D). In addition, the AEP group
participants’ self-esteem measured by Coopersmith’s Self-Esteem Inventory (SEI) also
significantly increased over time. In Marquez-Sterling et al.’s (2000) study of body
image, 20 pregnant women were randomly assigned either to an exercise intervention or
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control group, and participated in the 15-week study during the second trimester of
pregnancy. The exercise intervention group showed a significant improvement in the
Body Cathexis Score (Secord & Secord, 1953), which represents participant’s attitude
toward the physical self and the perception of body image.
More recently, Guszkowska (2011) conducted a study examining the relationship
between regular exercise program participation during pregnancy and perceived level of
labor anxiety. In the study, pregnant women in the exercise group (n=135) participated in
a 60-minute, low-intensity yoga, pilates, and ball exercise program at least twice a week,
while the sedentary non-exercising group (n=64) did not attend any exercise classes or
exercised at home. All participants were in the second or third trimester of their first
pregnancy and did not have any medical complications to exercise. After 12 weeks,
participants were asked to visualize their labor and respond to the State-Trait Anxiety
Inventory ([STAI], Spielberger, 1966) and Profile of Mood States ([POMS], McNair, Lorr,
& Droppleman, 1971) to assess the perceived anxiety and emotional state of an actual
labor. As compared to the sedentary group, pregnant women who engaged in a regular
exercise program had significantly better emotional state and lower levels of anxiety as
they visualized their own labor.
Guidelines for Exercise during Pregnancy
Government institutions and research associations have been interested in
exercise promotion among pregnant women. Specific guidelines have been presented to
promote pregnant women’s exercise behavior and health benefits.
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The American Congress of Obstetricians and Gynecologists (ACOG, 2002) and
the American College of Sports Medicine (ACSM, 2006) recommend 30 minutes or more
of moderate to vigorous exercise a day on most of the week during pregnancy. More
recently, the USDHHS (2008) released exercise guidelines for pregnant women.
According to the guidelines, at least 150 minutes of moderate-intensity aerobic activity
per week is advised for those who have not been engaged in regular exercise before
pregnancy. Further, under a health-care provider’s recommendations and adjustments,
healthy women who have been engaged in regular exercise may continue to do so
throughout the pregnancy and postpartum.
In addition to the health benefits and guidelines of exercise for pregnant women,
recent empirical studies also provide sufficient evidence supporting the safety of
exercising during pregnancy. After conducting a meta-analysis of 18 pregnancy exercise
intervention studies, Lokey et al. (1991) concluded that a variety of exercise interventions
following the ACOG (2002) recommendation were safe for the mother and the fetus.
Engaging in regular exercise for 43 minutes three times a week at a moderate intensity
did not show any adverse effect on gestation length, maternal weight gain, length of labor,
infant birth weight, or Appearance, Pulse, Grimace, Activity, and Respiration ([APGAR],
Apgar, 1953; Finster & Wood, 2005) scores which were examined immediately after birth.
Sternfeld, Quesenberry, Eskenazi, and Newman (1995) also found that exercise is
a safe means to gain the health benefits during pregnancy. In their cross-sectional survey
study, the researchers followed pregnant women (n=388) from an average of 16.5 weeks
of gestation to delivery to examine the effect of exercise on birth outcomes. The large
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survey data indicated that participation in moderate to vigorous regular aerobic exercise
during pregnancy was not associated with any adverse effect on birth weight or other
maternal and infant outcomes.
Recently, O’Connor, Poudevigne, Cress, Motl, and Clappstrength (2011) found
that strength training is safe and efficacious for pregnant women. A total number of 32
pregnant women participated in a supervised low-to-moderate intensity resistance
training, twice a week for 12 weeks. They reported that no negative physical or
physiological changes (i.e., injuries, adverse symptoms, blood pressures) occurred as a
result of the exercise intervention, while still gaining the positive effects of strength
training.
Prevalence of Exercise among Pregnant Women
Despite the health benefits and safety of exercise during pregnancy, many
pregnant women still remain sedentary. Zhang and Savitz (1996) first examined the
prevalence of exercise during pregnancy in the United States. Women who had a
successful delivery and participated in the National Maternal and Infant Health Survey in
1988 were randomly recruited from 48 states, the District of Columbia, and New York
City, and completed a cross-sectional survey. The result from the survey showed that 58%
of women are sedentary during pregnancy.
Women seem to be less active during pregnancy. Fell, Joseph, Armson, and
Dodds (2008) recruited 1,737 Canadian pregnant women and compared the physical
activity level during pregnancy to the year before pregnancy. Physical activity level was
assessed by the Kaiser Physical Activity Survey (Sternfeld, Ainsworth, & Quesenberry,
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1999). The results indicated that all physical activity items (i.e., household and family
care, active living, sports and exercise) from the survey significantly decreased during
pregnancy, with sports and exercise decreasing the most.
Results from recent research also found that only a small proportion of pregnant
women engage in exercise which meets the current ACOG (2002) guideline (Evenson et
al., 2004; Evenson & Wen, 2010). In the earlier study among 1,979 participants who were
representative of the US population of pregnant women, only 15.8% met recommended
leisure-time activity. Similarly, in the later study, which analyzed the data from the 1999-
2006 National Health and Nutrition Examination Survey (n=1280), approximately 20%
of pregnant women met the current ACOG (2002) physical activity guideline.
Socio-demographic Features and Exercise during Pregnancy
Socio-demographic factors such as education, income, and ethnicity, play a
significant role in physical activity level during pregnancy. A positive relationship
between the level of education and exercise during pregnancy was consistent across
different populations from South America (Domingues & Barros, 2007), North America
(Hinton & Olson, 2001), and Europe (Owe, Nystad, & Bo, 2009). Women with higher
education and level tend to engage in regular exercise more frequently as compared to
those with lower education level. Ethnicity also plays a significant role in exercise during
pregnancy. Research shows that whites exercise more than the non-white population
(Evenson, Savitz, & Huston, 2004) while Asians seem to be the most sedentary ethnic
group during pregnancy (Zhang & Savitz, 1996).
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Higher income or socioeconomic status (SES) is a strong predictor of regular
exercise in the general population, and this relationship is also significant among
pregnant women. In their study of 386 normotensive pregnant women, Ning, Williams.
Dempsey, Sorensen, and Fredrick (2003) found that income was positively related to
exercise during pregnancy. Domingues and Barros (2007) interviewed 4,471 mothers in
southern Brazil, and reported that physical activity during pregnancy is strongly
associated with total family income. More recently, a consistent relationship between
income or SES and exercise during pregnancy was also reported in a cross-sectional
study of 762 pregnant women in Taiwan (Cheng et al., 2011)
Pregnant Women’s Exercise Behavior and Intention
Considering the health benefits and safety of exercise and prevalence of
inactivity during pregnancy, designing an effective intervention that can increase the
activity level and its adherence is necessary. As the first step, exploring psychosocial
determinants of pregnant women’s exercise behavior is a promising approach to
designing effective research interventions (Hausenblas & Symons Downs, 2004). For
example, finding barriers or facilitators of exercise during pregnancy may help future
intervention studies to bring higher physical activity level and adherence. Hausenblas,
Symons Downs, and their colleagues have conducted a series of studies using the Theory
of Planned Behavior (TPB) as a theoretical framework to explore the psychosocial
determinants of exercise behavior during pregnancy.
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The Theory of Planned Behavior
The TPB is social cognitive theory proposed by Ajzen (1991) that provides a
conceptual framework for predicting human behavior. According to the theory, an
individual’s intention to perform a behavior and perceived behavioral control are the key
predictors of his or her actual behavior. Intention reflects the motivational factors of
conducting a certain behavior; and it indicates a person’s degree of willingness to
perform a behavior. However, an individual’s motivation may not be the only appropriate
predictor of a behavior. For example, a group of people may have the same motivation to
maintain a healthy diet, but may end up with different diets because each person has
different opportunities and resources (e.g. money, availability, time). In other words,
people may have different control factors for performing a behavior, and those control
factors are represented by perceived behavioral control in the TPB framework. Perceived
behavioral control explains an individual’s perceived obstacles or confidence of
performing a behavior derived from both past experience and future anticipation.
According to the TPB, a person’s motivational factor (intention) is predicted by
three independent psychosocial determinants; attitude, subjective norm, and perceived
behavioral control. Attitude represents an individual’s beliefs about a specific behavior.
For example, people may have different beliefs or evaluations (e.g., favorable-
unfavorable, beneficial-harmful, and happy-unhappy) toward a behavior, and in the TPB,
attitude explains these beliefs and evaluations. Subjective norm explains the normative
factors of a person’s behavior. An individual’s perception about what significant others
(e.g., family members, friends) think about performing a certain behavior is explained
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through this construct. Perceived behavioral control also influences people’s intention
towards the behavior. As mentioned earlier, perceived behavioral control reflects an
individual’s perceived capability of performing a behavior, and predicts both intention
and behavior directly, according to the TPB framework.
TPB Research on Predicting Exercise Intention and Behavior
The TPB has been applied in many areas of research and shown to predict human
behavior. The TPB has provided an excellent theoretical framework for predicting
exercise behavior in research studies with many different populations (Biddle & Nigg,
2000). Blanchard (2008) used the TPB in his study of 76 Canadian cardiac- rehabilitation
participants to examine their exercise behavior during a 6-month home-based
rehabilitation program, and reported the potential effectiveness of the TPB. In their study
of 112 overweight women in the southern region of the US, Gardner and Hausenblas
(2004) applied the TPB to examine overweight women’s exercise and diet program
participation. In their study, the TPB successfully predicted overweight women’s 4-week
exercise and diet behavior, indicating that the TPB may be an effective framework to
design a weight control intervention.
Symons Downs (2006) examined the predictive utility of the TPB with 63 low-
income and ethnically diverse postpartum women’s exercise intention. The study found
that participants’ attitude and subjective norm predicted 66% of the variance in their
exercise intention, and ethnicity did not moderate the TPB constructs in explaining
women’s exercise intention during the postpartum period. The results suggested that the
TPB effectively predicts exercise behavior of ethnically diverse postpartum women.
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More recently, Karvinen et al. (2009) used the TPB to examine 397 Canadian cancer
survivors’ determinants of exercise. They found that some medical, social, and
demographical variables may moderate bladder cancer survivors’ exercise behavior and
intention, but these relationships were clearly mediated by the TPB constructs, indicating
that the TPB is potentially useful theoretical model for designing exercise project in the
bladder cancer survivor population. The TPB model successfully predicted exercise
intention and behavior among the cancer survivors, suggesting that the TPB may be a
good theoretical framework to design an effective intervention.
Symons Downs and Hausenblas (2005) conducted a meta-analysis of 111
exercise studies which used the TPB as a theoretical framework, and found that the TPB
is an effective theoretical framework to examine and understand exercise behavior.
According to the review, a strong association was found between attitude and intention,
and also between perceived behavioral control, intention, and exercise behavior. The
review also found intention as a predictor of exercise behavior, and attitude and perceived
behavioral control as predictors of intention.
Relationship between TPB Constructs and Pregnancy
Research indicates that the three constructs of TPB which predict intention are
closely related to the characteristics of exercising during pregnancy. First, exercise during
pregnancy is determined by several belief factors (attitude). For example, the safety issue
is an important belief factor for exercising during pregnancy. In a study of 57 British
pregnant women (Clarke & Gross, 2004), one third of the participants chose the risk of
health to an unborn baby as a primary reason for not being active during pregnancy. Also,
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Duncombe Wertheim, Skouteris, Paxton, & Kelly (2007) conducted a survey study
examining pregnant women’s belief about the safety of exercise during pregnancy. A
majority of pregnant women had safety concerns about their own and baby’s health,
regardless of the intensity and frequency of exercise. Second, subjective norm seems to
be a prominent determinant of women’s exercise participation during pregnancy.
Although findings are not uniform, research suggests that many different significant
others may have a significant influence on pregnant women’s exercise behavior.
Symons Downs and Hausenblas (2004) conducted a survey study to examine
exercise beliefs during pregnancy and postpartum. With 74 participants who answered a
questionnaire designed to assess their behavioral, normative, and control beliefs about
exercise during pregnancy. They picked their husbands or fiancés (36.5%), children
(17.6%), other family members (14.9%), friends (12.2%), health care professionals
(2.7%), and gym instructors (2.7%) as significant others who have the most influence on
exercising during pregnancy. In their study of 57 pregnant women, Clarke and Gross
(2004) used a structured interview and the Fetal Health Locus of Control Scale (Labs &
Wurtele 1986) to asses women’s physical activity participation and the most influential
person regarding exercising during pregnancy. The result indicates that the majority of
women are influenced by their friends and family members in choosing to exercise
during pregnancy. Krans et al. (2005) conducted a survey study among 211 pregnant
women to find pregnancy exercise beliefs and influences. Most of the participants (41%)
replied that their physicians had the most influence on their maternal exercise behavior
and belief. In their study of a large number of Norwegian pregnant women (n=34,508),
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Owe, Nystad, and Bo (2009) found that women who had pregnancy-related health issues
were more likely to be sedentary during pregnancy. Not surprisingly, women who self-
reported their general health as good or excellent were more likely to participate in
regular physical activity than those who reported their health as fair or poor (Evenson,
Savitz, & Huston, 2004). Third, research suggests that control factors (perceived
behavioral control) may influence pregnant women’s exercise intention. In their narrative
review, Schoenfeld and Tiriyaki-Sonmez (2011) found that a number of studies indicate
health related issues, maternal time constraint, and child care may affect women’s
perceived behavioral control on exercising during pregnancy.
TPB Research on Exercise during Pregnancy
Hausenblas and Symons Downs (2004) examined pregnant women’s exercise
behavior and intention during the first trimester of pregnancy. A total of 104 participants
who were in the first trimester of pregnancy completed a questionnaire that assessed their
exercise behavior and intention within the TPB constructs. A substantial number (58.7%)
of the participants had a relatively medium-to-high annual income of $40,000 to
$100,000, and were Caucasian (87.5%). Exercise behavior was assessed by the Leisure-
Time Exercise Questionnaire ([LTEQ], Godin & Shephard, 1985). Hierarchical
regression analysis (HRA) showed that, while both being a significant predictor,
perceived behavioral was a stronger predictor of exercise behavior, as compared to
intention. And, attitude and subjective norm significantly predicted exercise intention
during the first trimester of pregnancy.
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Symons Downs and Hausenblas (2003) also used the TPB to explore pregnant
women’s exercise behavior and intention during the second trimester of pregnancy. The
majority of the 89 participants was Caucasian (89%) and had an annual family income
between $40,000 and $100,000. According to the HRA, only exercise intention
significantly predicted exercise behavior, and attitude was the strongest predictor of
exercise intention during the second trimester of pregnancy.
Symons Downs and Hausenblas (2007) examined pregnant women’s exercise
behavior and intention during the third trimester by using similar methods to previous
studies. Among 62 participants, 91.9% were Caucasian and 75.8% had an annual family
income between $40,000 and $100,000. Statistical analyses indicated that intention
predicted exercise behavior and subjective norm predicted exercise intention of pregnant
women during the third trimester.
Despite the contributions made so far, there is still some room for furthering our
knowledge about pregnant women’s exercise behavior and intention. We know about
exercise behavior and intention among pregnant women from middle-to-upper classes.
However, we do not know about low SES pregnant women’s psychosocial determinants
of exercise based on the TPB constructs.
Summary
Exercise during pregnancy is a safe activity that results in both physiological and
psychological benefits. However, a substantial number of pregnant women remain
sedentary (Fell et al., 2008; Zhang & Savitz, 1996) and only a small number of them
meet the current exercise guidelines (Evenson et al., 2004; Evenson & Wen, 2010).
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Recently, researchers applied the TPB to explore pregnant women’s exercise
behavior and intention. They have provided a better understanding of pregnant women’s
exercise behavior and a conceptual framework to design further interventions and
research during pregnancy (Hausenblas & Symons Downs, 2004). However, the majority
of the participants represent the middle-to-upper class population, and the researchers
failed to look at low SES pregnant women’s exercise behavior and intention. Thus, the
purpose of this study is to examine the exercise behaviors of low SES pregnant women
within the TPB framework.
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CHAPTER III
METHODS
The purpose of this study was to examine factors related to pregnant women’s
exercise behavior with the TPB. Survey methods were used with low SES women who
are in the first trimester of pregnancy to address the purpose and research questions of
this study.
Participants
Participants were women in their first trimester of pregnancy, recruited from a
community health program, Adopt-A-Mom, in Guilford County, North Carolina. The
program provides prenatal care to pregnant women who have low family income, do not
have a health insurance, and are not eligible for Medicaid. The program mainly focuses
on infant mortality prevention, which is defined as the death of a child born alive before
their first birthday. The Adopt-A-Mom program has an annual enrollment of 300 pregnant
women who usually visit the Guilford County social services office and meet the program
director during their first trimester of pregnancy. Based on the 𝑅2 value of previous
research of Hausenblas and Symons Downs (2004), sample size of 40 was needed to
obtain a power of .81 with moderate effect size of .26 for predicting exercise behavior
with all constructs of the TPB. However, the Adopt-A-Mom program director only
allowed to access 50 participants for the study, and the sample showed relatively low
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effect size of .10. Achieved power was .41, and it would have been .83 if 120 participants
were recruited.
Measures
Several different measures were included in the survey: a demographic
questionnaire and several items that have been used in previous studies with pregnant
women to examine the TPB constructs. An item was added in the demographic
questionnaire to assess physical activity level. Further information regarding this physical
activity item is provided in later part of this section.
According to the Adopt-A-Mom program director, approximately 90% of the
program participants indicated their primary language as either English or Spanish. Thus,
all questionnaires were provided both in English and Spanish. Initial translation of the
questionnaires were conducted by Fluent Language Solutions Inc., a professional
translation service company located in Charlotte, NC. The Adopt-A-Mom program
coordinator who is Spanish-English bilingual did a back translation to check the accuracy
of the initial translation. Copies of all measures including both English and Spanish
versions are provided in the Appendix.
Demographic questionnaire
The demographic questionnaire assessed age, education, employment, marital
status, number of children, and ethnicity. Family income was not asked because all
prospective participants were expected to meet the Adopt-A-Mom program eligibility
criteria. According to the Adopt-A-Mom and North Carolina Medicaid eligibility, all
participants would have an annual family income less than $40,000
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Physical Activity Measure
The researcher originally planned to use the LTEQ (Godin & Shephard 1985)
which was used in the previous study of Hausenblas and Symons Downs (2004) to assess
physical activity level among low SES pregnant women. However, the measure was
accidently omitted from the questionnaire. No data was available to assess physical
activity as a continuous variable. Thus, the researcher chose to use a leisure-time physical
activity item that was included in the demographic questionnaire to assess physical
activity as a categorical variable. This question, which was used in Centers for Disease
Control and Prevention’s (CDC) Morbidity and Mortality Weekly Report (MMWR, 2011)
was added in the demographic questionnaire to assess the prevalence of leisure-time
physical activity among the participants; “During the past month, other than your regular
job, did you participate in any physical activities or exercise such as running, calisthenics,
golf, gardening, or walking for exercise?”
The TPB Constructs: Intention, Attitude, Subjective Norm, and Perceived Behavioral
Control
The TPB constructs (i.e., intention, attitude, subjective norm, and perceived
behavioral control) predicting pregnant women’s exercise behavior were assessed with
the TPB global items which was used by Hausenblas and Symons Downs (2004).
Pregnant women’s intention to exercise during the first trimester was measured by the
statements: ‘It is my intention to exercise during my first trimester of pregnancy’, ‘I
intend to exercise with the following regularity during my first semester’ or ‘I intend to
exercise at least three times per week during my first semester’ with a seven-point scale
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25
anchored from 1 (strongly disagree) to 7 (strongly agree). Hausenblas and Symons
Downs (2004) did not report the internal consistency reliability of this scale. However,
result from reliability analysis indicated that items assessing exercise intention was
sufficient for the present study. Cronbach alpha value for these items is reported in the
result section.
Pregnant women’s attitude toward exercise during the first trimester was assessed
by the item: ‘ Exercising during my first trimester of pregnancy is/will be…’. This item is
followed by a set of bipolar adjectives representing positive and negative attitude toward
exercise behavior: useless-useful, harmful-beneficial, bad-good, foolish-wise,
unenjoyable-enjoyable, boring (or uninteresting)-interesting, and unpleasant-pleasant.
Each item is rated on a 7-point scale and the sum of the scores from each item was used
for statistical analyses. In the previous study (Hausenblas & Symons Downs 2004), the
Cronbach alpha was 0.92 for this item.
Women’s subjective norm of exercise during the first trimester of pregnancy was
assessed by adding up the scores from the following two questions each with a seven-
point scale. The questions were: ‘Most people who are important to me think that I
should (or want me to) exercise regularly during my first trimester of pregnancy’
(strongly disagree-strongly agree), and ‘Most people who are important to me approve of
me exercising regularly during my first trimester’ (strongly disagree-strongly agree). The
cronbach alpha was 0.70 for this scale in the previous study (Hausenblas & Symons
Downs 2004).
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26
Perceived exercise behavior control was measured by three items with each on a
seven-point scale: ‘How much control do you have over exercising during your first
trimester of pregnancy?’ (very little control-complete control), ‘For me to exercise during
my first trimester of pregnancy is/will be…’ (extremely difficult-extremely easy), and ‘If
I want to, I can easily exercise during my first trimester of pregnancy’ (strongly agree-
strongly disagree). The scores from each item will be added up for statistical analyses.
Hausenblas and Symons Downs (2004) reported an internal consistency reliability of 0.90
for this scale.
Procedures
Prospective participants, on their first visit to the Adopt-A-Mom program office,
were asked whether or not they were willing to participate in the study examining their
exercise behaviors during the first trimester of pregnancy. Once they agreed to take part
in the research, they were given a study packet which consisted of a detailed cover letter,
an informed consent form, and research questionnaires (i.e. CDC’s leisure-time physical
activity item, TPB items, and demographic questionnaire). The packet was included in
the Adopt-A-Mom application and participants were asked to return the packet with the
application. Those participants who decided to participate in the study and completed the
questionnaire were given a complementary gift certificate of $5. All participants
completed the questionnaire in a private room at the Adopt-A-Mom office, and the
researcher provided the gift certificate in person.
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Statistical Analysis
Two separate statistical analyses were conducted to test the TPB variables within
the study hypotheses. In the first statistical analysis, multiple regression was used.
Pregnant women’s first trimester exercise intention was regressed on the three constructs
of the TPB predicting the intention; attitude, subjective norm, and perceived behavioral
control. In the second analysis, discriminant analysis was used to determine if the two
constructs of the TPB construct predicting the behavior; intention and perceived
behavioral control, could discriminate between the exercise and no-exercise groups.
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CHAPTER IV
RESULTS
The purpose of this study was to examine psychosocial determinants of exercise
among low-socioeconomic status pregnant women during their first trimester of
pregnancy by replicating the previous study of Hausenblas and Symons Downs (2004).
Multiple regression and discriminant analyses were used to find the relationship between
the TPB constructs and exercise behavior. TPB Global Items from the previous study and
CDC leisure time physical activity item were the primary measures used to address the
research questions.
Descriptive Information on the Sample
A total of 56 women in the first trimester of pregnancy participated in the study.
However, 6 questionnaire packets had missing data and were excluded for analyses. Thus
data from 50 participants were included in the analyses. Most of the pregnant women
participated in the study through the Adpot-A-Mom program were Hispanic (86%),
married (82%), part-time employed (32%) or unemployed (52%), had one (32%), two
(30%), three or more children (8%), and had a high school or associate degree (84%).
The average age of the participants was 29.06 (SD=5.40) years old. Descriptive statistics
for the sample are provided in Table 1.
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29
Table 1. Demographic characteristics of sample.
Characteristic N %
Age
≥35 years 25-34 years
≤25 years Ethnicity
White/Caucasian
African-American
Asian-Pacific Islander
Hispanic/Latino
Marital Status
Married
Single
Living with partner
Employment
Full-time
Part-time
Unemployed
Number of children
0
1
2
3
5
Education
Less than high school
High school
Associate degree
Bachelor’s degree
Graduate/Professional
10
25
15
2
2
3
43
41
4
5
8
16
26
15
16
15
3
1
3
17
25
2
3
20
50
30
4
4
6
86
82
8
10
16
32
52
30
32
30
6
2
6
34
50
4
6
Descriptive Analysis of the TPB and Physical Activity Measure
The TPB constructs and physical activity were the primary variables that address
the research questions of this study. The TPB constructs were measured by the TPB
Global Items used in the previous study of Hausenblas and Symons Downs (2004).
Reliability analysis was conducted and revealed that the measures were reliable for each
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30
TPB construct; intention (α=.800), attitude (α=.896), subjective norm (α=.910), and
perceived behavioral control (α=.858). All items for each TPB constructs contributed to
the total reliability and had positive item-total correlations. Hence, all items were used to
calculate the mean score of each TPB constructs and conduct statistical analyses.
An item from Centers for Disease Control and Prevention’s Morbidity and
Mortality Weekly Report (2011) was used to assess physical activity. Participants
responded Yes or No to this question. Therefore, physical activity outcome was used as a
categorical variable. The 50 participants were divided fairly equal regarding their leisure
time physical activity; 24 participants answered ‘Yes’ to the item while the other 26
answered ‘No’.
The TPB Model and Exercise Behavior
Predicting pregnant women’s first trimester exercise intention and behavior
within the TPB constructs was the main purpose of this study. According to the TPB
model, attitude, subjective norm and perceived behavioral control predict exercise
intention, and intention and perceived behavioral control predict exercise behavior.
Results from preliminary correlation analysis showed that only subjective norm, but not
attitude and perceived behavioral control, was significantly correlated to exercise
intention. Only perceived behavioral control, but not exercise intention, was significantly
correlated to exercise behavior. Correlations between exercise behavior and the TPB
constructs are presented in Table 2.
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Table 2. Correlations, means, and standard deviations of the TPB constructs.
Variable 2 3 4 5 M SD
1 Exercise
2 Intention
3 Attitude
4 Sub. Norm
5 PBC
-.169
-.163
.087
.037
.282*
.077
-.430*
-.013
.167
-.188
-
4.42
4.92
4.28
3.89
-
1.42
1.28
1.46
1.82
*Significant at the .05 level
Prediction of Exercise Intention
To address the first research question, a multiple regression analysis was used
with exercise intention regressed on attitude, subjective norm and perceived behavioral
control. According to the theoretical structure of the TPB (Ajzen, 1991), the three
constructs that predict intention were divided into two blocks for multiple regression
analyses. In the first block, exercise intention was regressed on attitude and subjective
norm, and perceived behavioral control was added in the second block. The analyses
indicated that attitude and subjective norm (block1) explained 9.1% of the variance of
intention. Although the beta weight of subjective norm was significant at p
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Table 3. Multiple regression analysis results for prediction of exercise intention.
Variable 𝐹𝑐ℎ𝑎𝑛𝑔𝑒 𝛽 P Block 1
Attitude
Sub. Norm
Block 2
Attitude
Sub. Norm
PBC
.198
-.110
.290
-.122
.303
.065
.105
.433
.043
.199
.400
.040
.659
Block 1: 𝑅2 = .091, 𝑅 = .302, 𝐹 =2.366 / Block 2: 𝑅2 = .095, 𝑅 = .309, 𝐹 =1.616
Thus, both preliminary correlation and multiple regression analysis failed to
support the TPB model for predicting exercise intention. Among three predictors; attitude,
subjective norm, and perceived behavioral control, only subjective norm was
significantly correlated to exercise intention. However, results from multiple regression
analysis indicated that the TPB model did not work in predicting exercise intention with
the study sample.
Prediction of Exercise Behavior
To address the second research question, discriminant analysis was conducted to
determine the relationship between the TPB constructs and exercise behavior. Results
from the analysis indicated that exercise intention and perceived behavioral control,
together, significantly, Wilks’ Lambda = .784, 𝜒2=11.422, p =.003, discriminated
between the two groups (exercise and non-exercise), explaining 46.4% of the variance of
the behavior. Results from the discriminant analyses are presented in Table 4.
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Table 4. Discriminant analyses results for predicting exercise behavior.
Variable Wilks’
Lambda 𝜒2 Canonical
correlation p Discriminant Func.
Coefficient
Disc. Func.
Intention
PBC
.784
11.422
.464
.003*
.419
.949
*Significant at the .05 level
A step-wise discriminant analysis was also conducted and only perceived
behavioral was entered, and had a significant, Wilks’ Lambda = .815, 𝜒2 = 9.731, p
=.002, canonical correlation to exercise behavior. Exercise intention did not significantly
contribute to the variance of exercise behavior. As the result shows, perceived behavioral
control was the stronger contributor to the discriminant function. Thus, the TPB model
predictions of exercise behavior were partially supported, as perceived behavioral control
predicted exercise behavior. However, exercise intention did not discriminate between
exercise and non-exercise groups.
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CHAPTER V
DISCUSSION
The primary research questions examined in this study are 1) Do pregnant
women’s first trimester exercise attitude, subjective norm, and perceived behavioral
control predict their exercise intention; and 2) do pregnant women’s first trimester
exercise intention and perceived behavioral control predict their exercise behavior. The
results did not support the first hypothesis predicting exercise intention, and partially
supported the second hypothesis predicting exercise behavior. Among the three constructs
predicting exercise intention within the TPB model, only subjective norm was
significantly correlated to exercise intention, and multiple regression analysis indicated
that the TPB model did not work for predicting exercise intention of this sample. For
predicting exercise behavior, only perceived behavioral control, but not exercise intention,
was significantly related to exercise behavior, and discriminated the exercise and non-
exercise group. These results partially support the second research hypothesis with
perceived behavioral control being the only significant predictor of exercise behavior. In
the following section, study results are discussed in detail, followed by future research
directions.
In contrast to the previous research of Hausenblas and Symons Downs (2004),
attitude, subjective norm, and perceived behavioral control did not predict exercise
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intention in the first trimester of pregnancy. This result indicates that the theoretical
framework of the TPB does not work in this sample, and may suggest that other variables
are affecting their exercise intention. Some characteristics of the sample may be possible
underlying variables. Demographic data of the sample showed that the majority of
participants (70%) already had one or more children and generally had very low income
according to the Adopt-A-Mom program admission criteria. It is plausible that barriers
such as maternal time constraint (Schoenfeld & Tiriyaki-Sonmez, 2011) or burdens of
everyday life made it difficult to measure exercise intention, which is in the leisure-time
domain. A comment from the Adopt-A-Mom program coordinator (V. Santolim, personal
communication, Apr. 30, 2012) supports this point:
It is very difficult to figure out what each of them is actually thinking about
health related issues. For example, when I talk about healthy food and nutrition,
one’s response may vary even within a minute. Many participants would easily
agree about choosing healthy foods, but in the next couple of minutes the same
person may suddenly change to an advocate of fast foods. Some participants
even say choosing fast food is a bad choice for health but it is also a privilege to
go to McDonald’s considering the past life in Mexico. I don’t know exactly why
these are happening, but I can clearly notice while talking to them that life issues
such as financial or immigration status problems are affecting their thoughts and
behavior.
Only perceived behavioral control, but not intention predicted exercise behavior
in this study. This result partially supports the previous study finding that perceived
behavioral control and intention both significantly predicted exercise behavior, with
perceived behavioral control being a stronger predictor (Hausenblas & Symons Downs,
2004). This may indicate that pregnant women’s perceived efficacy (i.e., perceived
behavioral control) plays a critical role during the first trimester for exercise behavior.
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This result may allow researchers and health care providers to target pregnant women’s
perceived capability of exercise when designing an exercise intervention program for a
low-socioeconomic sample. Because perceived behavioral control was the only
significant predictor of exercise behavior, and its prediction was strong, it is plausible to
consider using self-efficacy (Bandura, 1997) theory as a theoretical framework in
predicting exercise behavior among similar samples. Self-efficacy is a model that focuses
on a person’s belief or confidence in a specific situation, and it has shown strong
prediction ability in exercise behavior research (Feltz & Lrigg, 2001). Self-efficacy
theory may provide ample information regarding pregnant women’s perceived control of
exercise that can help designing an effective exercise intervention program for low-
socioeconomic women in the first trimester of pregnancy.
Notwithstanding the findings from this study, there are number of limitations
that should be considered. First, the majority of participants were Hispanic (n=43, 86%)
with Spanish as a primary language. People from different ethnic background may have
diverse cultural aspects, social relationships, or beliefs and culture may influence the
efficacy of the TPB in predicting exercise behavior. Results from recent studies are
relatively inconsistent on the moderating effect of ethnicity in explaining exercise
behavior with the TPB framework. For example, ethnicity did moderate the relationship
between the TPB constructs and exercise behavior among the US college students
(Blanchard, 2007), while no moderating effect was found among postpartum women
(Symons Downs, 2006). However, no study so far has examined the utility of the TPB in
predicting exercise behavior among an Hispanic pregnant sample, or tested the
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37
moderating effect of ethnicity within the TPB framework with an ethnically diverse
pregnant sample. Future studies might investigate these areas for further elucidating
exercise intention and behavior during pregnancy.
Second, methodological limitations exist with measure of the exercise behavior.
First, the item employed in this study measured physical activity as a dichotomous
variable. Participants were divided into two groups; exercise and non-exercise group, by
answering yes or no to the physical activity item. Thus, information regarding the
frequency and intensity of exercise was limited. Second, the physical activity measure
was logically inappropriate for the model and predicting future behavior. The item asked
about the past (one month) leisure-time exercise behavior, and there was no further
measure or attempt to actually predict exercise behavior after completing the
questionnaire. Thus, predicting past behavior with present TPB constructs was not a
logically sound method for examining . Future research may consider adding follow up
physical activity measures after completing the initial survey for predicting exercise
behavior.
Third, the unique environment of the study procedure may have influenced the
participants’ response to the questionnaire. The research questionnaire packet was
included in the Adopt-A-Mom application, and during the initial visit, participants were
basically applying for financial assistance. Therefore, despite the information provided in
the consent form regarding participant’s right and confidentiality, participants might have
felt some pressure for completing the questionnaire. Future studies should try to recruit
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38
low-socioeconomic status participants separate from such settings and any form of social
or personal pressure.
Despite the limitations, this study is one of the first to examine low-
socioeconomic status women’s exercise intention and behavior during the first trimester
of pregnancy. Some methodological limitations must be overcome in following research
to further our knowledge regarding pregnant women’s exercise behavior. Exploring the
moderating effect of ethnicity and employing logically sound physical activity measures
for behavioral prediction may be promising direction for future research. Our goal is to
continue this endeavor to promote regular exercise during pregnancy for healthier moms
and babies.
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39
REFERENCES
Ajzen, I. (1991). The theory of planned behavior. Organizational Behavior and Human
Decision Processes, 50, 179-211
American College of Sports Medicine. (2006). Guidelines for exercise testing and
prescription, 7th ed. Philadelphia: Lippincott Williams & Wilkins.
American Congress of Obstetricians and Gynecologists. (2002). Exercise during
pregnancy and the postpartum period (ACOG Committee Opinion No. 267). Obstetrics
& Gynecology, 99(1), 171-173.
Apgar, V. (1953). A proposal for a new method of evaluation of the new infant. Current
Researches In Anesthesia & Anlagesia, 32(4), 260-267.
Bandura, A. (1997). Self-efficacy: The exercise of control. New York: Freeman.
Biddle, S. J. H., & Nigg, C. R. (2000). Theories of exercise behavior. International
Journal of Sport Psychology, 31(2), 290-304.
Blanchard, C. (2008). Understanding exercise behaviour during home-based cardiac
rehabilitation: a theory of planned behaviour perspective. Canadian Journal of
Physiology & Pharmacology, 86(1), 8-15.
-
40
Bungum, T. J., Peaslee, D. L., Jackson, A. W., & Perez, M. A. (2000). Exercise during
pregnancy and type of delivery in nulliparae. Journal of Obstetric, Gynecologic, and
Neonatal Nursing, 29(3), 258-264.
Centers for Disease Control and Prevention. (2011, December 9). State-specific
prevalence of no leisure-time physical activity among adults with and without doctor-
diagnosed arthritis – United States, 2009. Morbidity and Mortality Weekly Report,
60(48), 1641-1645.
Cheng, Y., Huang, Y., Lu, F., Wu, J., Lin, L. L., Chang, C., & Yang. Y. (2011). The
correlates of leisure time physical activity among an adults population from southern
Taiwan. BioMed Central Public Health, 11(1), 427-435.
Clapp, J. F. (2008). Long-term outcome after exercising throughout pregnancy: Fitness
and cardiovascular risk. American Journal of Obstetrics and Gynecology, 199(5),
489.e1-489.e6.
Clapp, J. F., Kim, H., Burciu, B., & Lopez, B. (2000). Beginning regular exercise in early
pregnancy: Effect on fetoplacental growth. American Journal of Obstetrics and
Gynecology, 183(6), 1484-1488.
Clapp, J. F., Rokey, R., Treadway, J. L., Carpenter, M. W., Artal, R. M., & Warrens, C.
(1992). Exercise in pregnancy. Medicine and Science in Sports and Exercise, 24(6),
294-300.
Clarke, P. E., & Gross, H. (2004). Women’s behaviour, beliefs and information sources
about physical exercise in pregnancy. Midwifery, 20(2), 133-141.
-
41
Domingues, M. R., & Barros, A. J. (2007). Leisure-time physical activity during
pregnancy in the 2004 Pelotas Birth Cohort Study. Revista De Saude Publica, 41(2),
173-180.
Duncombe, D., Wertheim, E. H., Skouteris, H., Paxton, S. J., & Kelly, L. (2007). Factors
related to exercise over the course of pregnancy including women’s beliefs about the
safety of exercise during pregnancy. Midwifery, 25(4), 430-438.
Evenson, K., Savitz, D., & Huston, S. (2004). Leisure-time physical activity among
pregnant U.S. women. Paediatric and Perinatal Epidemiology, 18(6), 400-407.
Evenson, K., & Wen, F. (2010). National trends in self-reported physical activity and
sedentary behaviors among pregnant women: NHANES 1999-2006. Preventive
Medicine, 50(3), 123-128.
Finster, M., & Wood, M. (2005). The Apgar score has survived the test time.
Anesthesiology, 102(4), 855-857.
Fell, D. B., Joseph, K. S., Armson, B. A., & Dodds, L. (2008). The impact of pregnancy
on physical activity level. Maternal and Child Health Journal, 13(5), 597-603.
Gardner, R. E., & Hausenblas, H. A. (2004). Exercise and diet beliefs of overweight
women participating in an exercise and diet program: An elicitation study using the
theory of planned behavior. Journal of Applied Biobehavioral Research, 9(3), 188-200.
Feltz, D. L., & Lrigg, C. D. (2001). Self-efficacy belifs of athletes, teams, and coaches. In
R. N. Singer, H. A. Hausenblas & C. M. Janelle (Eds.), Handbook of sport psychology
(pp.340-361). New York: Wiley & Sons.
-
42
Godin, G., & Shephard, R. J. (1985). A simple method to assess exercise behavior in the
community. Canadian Journal of Applied Sport Science, 10(3), 141-146.
Green, S. B. (1991). How many subjects does it take to do a regression analysis.
Multivariate Behavioral Research, 26(3), 499-510.
Guszkowska, M. (2011). Physical avtivity in relation to affective states and labor anxiety
in pregnant women. Medicina Sportiva, 15 (3),114-118.
Hagger, M. S., Chatzisarantis, N. L. D., & Biddle, S. J. H. (2002). A meta-analytic
review of the theories of reasoned action and planned behavior in physical activity:
Predictive validity and the contribution of additional variables. Journal of Sport &
Exercise Psychology, 24(1), 3-32.
Hausenblas, H. A., Carron, A. V., & Mack, D. E. (1997). Application of the theories of
reasoned action and planned behavior to exercise behavior: A meta-analysis. Journal
of Sport & Exercise Psychology, 19(1), 36-51.
Hausenblas, H. A., & Symons Downs, D. (2004). Prospective examination of the Theory
of Planned Behavior applied to exercise behavior during women’s first trimester of
pregnancy. Journal of Reproductive and Infant Psychology, 22(3), 199-210.
Hausenblas, H. A., Symons Downs, D., Giacobbi, P., Tucitto, D., & Cook, B. (2008). A
multilevel examination of exercise intention and behavior during pregnancy. Social
Science & Medicine, 66(12), 2555-2561.
Hinton, P. S., & Olson, C. M. (2001). Predictors of pregnancy-associated change in
physical activity in a rural white population. Maternal and Child Health Journal, 5(1),
7-14.
-
43
Jackson, M. R., Gott, P., Lye, S. J., Knox-Ritchie, J. W., & Clapp, J.F. (1995). The
effects of maternal aerobic exercise on human placental development: Placental
volumetric composition and surface areas. Placenta, 16(2), 179-191.
Karvinen, K. H., Courneya, K. S., Plotnikoff, R. C., Spence, J. C., Venner, P. M., & North,
S. (2009). A prospective study of the determinants of exercise in bladder cancer
survivors using the theory of planned behavior. Support Care Cancer, 17, 171-179.
Koniak-Griffin, D. (1994). Aerobic exercise, psychological well-being, and physical
discomforts during adolescent pregnancy. Research in Nursing & Health, 17(4), 253-
263.
Krans, E. E., Gearhart, J. G., Dubbert, P. M., Klar, P. M., Miller, A. L., & Replogle, W.
H. (2005). Pregnant women’s beliefs and influences regarding exercise during
pregnancy. Journal of Mississippi State Medical Association, 46(3), 67-73.
Labs, S. M., & Wurtele, S. K. (1986). Fetal health locus of control scale: development
and validation. Journal of Consulting and Clinical Psychology, 54(6), 814-819.
Lokey, E. A., Tran, Z. V., Wells, C. L., Myers, B. C., & Tran, A. C. (1991). Effects of
physical exercise on pregnancy outcomes: A meta-analytic review. Medicine and
Science in Sports and Exercise, 23(11), 1234-1239.
Marquez-Sterling, S., Perry, A. C., Kaplan, T. A., Halberstein, R. A., & Signorile, J. F.
(2000). Physical and psychological changes with vigorous exercise in sedentary
primigravidae. Medicine and Science in Sports and Exercise, 32(1), 58-62.
McNair, D. M., Lorr, M., & Droppleman, L. F. (1971). Manual for the profile of mood
and states. San Diego: Educational and Industrial Testing Service.
-
44
Ning, Y., Williams, M. A., Dempsey, J. C., Sorensen, T. K., & Fredrick, I. O. (2003).
Correlates of recreational physical activity in early pregnancy. Journal of Maternal-
Fetal and Neonatal Medicine, 13, 385-393.
O’Connor, P J., Poudevigne, M. S., Cress, M. E., Motl, R. W., & Clapp, J. F. (2011).
Safety and efficacy of supervised strength training adopted in pregnancy. Journal of
Physical Activity and Health, 8(3), 309-320.
Owe, K. M., Nystad, W., & Bo, K. (2009). Correlates of regular exercise during
pregnancy: the Norwegian mother and child cohort study. Scandinavian Journal of
Medicine and Science in Sports, 19, 637-645.
Pereira, M. A., FitzGerald, S., Gregg, E., Joswiak, M., Ryan, W. J., Suminiski, R., . . .
Zumda, J. M. (1997). A collection of physical activity questionnaires for health-related
research. Medicine and Science in Sport and Exercise, 29(6 Suppl.), S1-205.
Polly, B. A., Wing, R. R., & Sims, C. J. (2002). Randomized controlled trial to prevent
excessive weight gain in pregnant women. International Journal of Obesity, 26(11),
1494-1502.
Schoenfeld, B., & Tiriyaki-Sonmez, G. (2011). Overcoming psychosocial barriers to
maternal exercise: intervention strategies to improve participation and adherence.
Biomedical Human Kinetics, 3, 61-66.
Secord, P. F., & Secord S M. (1953). The appraisal of body cathexis: Body-cathexis and
the self. Journal of Consulting Psychology, 17(5), 343-347.
Spielberger, C. D. (1966). Anxiety and behavior. New York: Academic Press.
-
45
Sternfeld, B., Ainsworth, B. E., & Quesenberry, C. P. (1999). Physical activity patterns in
a diverse population of women. Preventive Medicine, 28(3), 313-323
Sternfeld, B., Quesenberry, C. P., Eskenazai, B., & Newman, L. A. (1995). Exercise
during pregnancy and pregnancy outcome. Medicine and Science in Sports and
Exercise, 27(5), 634-640.
Symons Downs, D. (2006). Understanding exercise intention in an ethnically diverse
sample of postpartum women. Journal of Sport and Exercise Psychology, 28, 159-170.
Symons Downs, D., & Hausenblas, H. A. (2003). Exercising for two: Examining
pregnant women’s second trimester exercise intention and behavior using the
framework of the theory of planned behavior. Women’s Health Issues, 13(6), 222-228.
Symons Downs, D., & Hausenblas, H. A. (2004). Women’s exercise beliefs and
behaviors during their pregnancy and postpartum. Journal of Midwifery and Women’s
Helath, 49(2), 138-144.
Symons Downs, D., & Hausenblas, H. A. (2005). The theories of reasoned action and
planned behavior applied to exercise: a meta-analytic update. Journal of Physical
Activity and Health, 2(1), 76-97.
Symons Downs, D., & Hausenblas, H. A. (2007). Pregnant women’s third trimester
exercise behavior, body mass index, and pregnancy outcomes. Psychology and Health,
22(5), 545-559.
United States Department of Health and Human Services (2000). Healthy People 2010.
Washington, D.C.
-
46
United States Department of Health and Human Services. (2008). 2008 Physical activity
guidelines for Americans. Washington, D.C.
Yeo, S. (2009). Adherence to walking or stretching, and risk of preeclampsia in sedentary
pregnant women. Research in Nursing & Health, 32(4), 379-390.
Zhang, J., & Savitz, D. A. (1996). Exercise during pregnancy among US women. Annals
of Epidemiology, 6(1), 53-59.
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APPENDIX A
MEASURES
Demographic Questionnaire (English Version)
1. Age:
2. Race/Ethnicity (circle): White/Caucasian African-American/Black Native American
Asian/Pacific Islander Hispanic/Latina/o Other/Mixed
3. Marital status (circle): Married Single (never married) Divorced Living with partner
4. Employment (circle): Full-time Part-time Not employed
5. When is your due date? (mm/dd/yyyy)
6. Is this your first pregnancy (circle)? Yes No
7. How many children do you have (circle)? 1 2 3 4 5+
8. Please indicate the highest level of education completed (circle):
Less than high school High school
Associate degree (Community college)
Bachelor’s degree Graduate or professional degree
9. What is your primary language (circle)? English Spanish Other
10. During the past month, other than your regular job, did you participate in any physical activities or exercises such as running, calisthenics, golf,
gardening, or walking for exercise (circle)?
Yes No
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Theory of Planned Behavior Global Items (English Version)
Instructions: The following questions pertain to DURING YOUR FIRST TRIMESTER
of pregnancy. Choose your answer by circling the number that most appropriately
answers the statement for you.
1. For me to exercise regularly during the first trimester of pregnancy will be: Useless Useful
1 2 3 4 5 6 7
2. I intend to exercise regularly during my first trimester. Strongly Strongly
Disagree Agree
1 2 3 4 5 6 7
3. Most people who are important to me would like me to exercise regularly during my first trimester
Strongly Strongly
Disagree Agree
1 2 3 4 5 6 7
4. For me to exercise regularly during my first trimester will be: Harmful Beneficial
1 2 3 4 5 6 7
5. For me to exercise regularly during my first trimester will be: Extremely Extremely
Difficulut Easy
1 2 3 4 5 6 7
6. For me to exercise regularly during my first trimester will be: Bad Good
1 2 3 4 5 6 7
7. Most people who are important to me think that I should exercise regularly during my first trimester.
Strongly Strongly
Disagree Agree
1 2 3 4 5 6 7
8. For me to exercise regularly during my first trimester will be: Foolish Wise
1 2 3 4 5 6 7
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9. I intend to exercise with the following regularity during my first trimester: Not at all Everyday
1 2 3 4 5 6 7
10. For me to exercise regularly during my first trimester will be: Unpleasant Pleasant
1 2 3 4 5 6 7
11. For me to exercise regularly during my first trimester will be: Unenjoyable Enjoyable
1 2 3 4 5 6 7
12. If I want to, I could easily exercise during my first trimester. Strongly Strongly
Disagree Agree
1 2 3 4 5 6 7
13. Most people who are important to me want me to exercise regularly during my first trimester.
Strongly Strongly
Disagree Agree
1 2 3 4 5 6 7
14. For me to exercise regularly during my first trimester will be: Boring Interesting
1 2 3 4 5 6 7
15. How much control do you have over exercising during your first trimester? Very Little Complete
Control Control
1 2 3 4 5 6 7
16. I intend to exercise at least three times per week during my first trimester. Definitely not Definitely
1 2 3 4 5 6 7
17. Most people who are important to me approve of me exercising regularly during my first trimester.
Strongly Strongly
Disagree Agree
1 2 3 4 5 6 7
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18. For me to exercise regularly during my first trimester will be: Uninteresting Interesting
1 2 3 4 5 6 7
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Demographic Questionnaire (Spanish Version)
1. Edad:
2. Raza/etnia (circule):
Blanco/caucásico Negro/Afro Americano Nativos americanos
Asia y el Pacífico isleños Hispano/Latina/o otro/mixto
3. Estado civil (circule):
Casada Soltera (nunca casada) Divorciada Vive con pareja
4. Empleo (circule):
Empleados a tiempo completo A tiempo parcial Sin empleo
5. ¿ Cuando es la fecha de nacimiento de su bebe? (dd/mm/aaaa)
6. ¿ Este es su primer embarazo (circule)? Sí No
7. ¿Cuántos niños ya tiene (circule)? 1 2 3 4 5+
8. Por favor indicar su nivel mal alto de educación:
Menos de la escuela secundaria Secundaria completa
Graduación en el colegio de la comunidad Grado de Bachiller
Graduado o profesional
9. ¿Cuál es su idioma principal? Inglés Español Otro
10. . Durante el mes pasado, además de su trabajo regular, ¿participó usted en algunas actividades físicas o ejercicios tales como correr, calistenia, golf,
jardinería o caminar (marque con un círculo la respuesta correcta)?
Si No
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Theory of Planned Behavior Global Items (Spanish Version)
1. Para mi, hacer ejercicio regularmente durante el primer trimestre de embarazo será:
Inútil Ú til
1 2 3 4 5 6 7
2. Yo tengo la intención de hacer ejercicio regularmente durante mi primer
trimestre.
Fuertemente Fuertemente
de acuerdo en desacuerdo
1 2 3 4 5 6 7
3. La mayoría de las personas que son importantes para mí quisieran que Yo
hiciera ejercicios regularmente durante mi primer trimestre.
Fuertemente Fuertemente de
acuerdo en desacuerdo
1 2 3 4 5 6 7
4. Para mí, hacer ejercicio regular